I also found thia Youtube video of a wheelchair accessible balloon.
http://www.youtube.com/watch?v=RRAzhAocuLQ Keep in mind that balloon landings can be an adventure. If wind picks up the gondola often bounces along the ground as the balloon deflates. I would definitely go in a manual chair that can be fastened down, or tranfer into a seat. Powerchairs could pose a danger to others on a bumpy landing.
